CCR7 and activated PI3K-delta syndrome: Notably, both CCR7 and CD62L are expressed at lower levels on T cells in peripheral blood from APDS/PASLI patients, which exhibit reduced CCR7+ naïve and central memory T cells, and a greater abundance of CD45RA−CCR7− effector memory and CD45RA+CCR7− terminal effector memory CD8+ T cells relative to controls (19).